This invention pertains machines that extract energy from ocean wave motion, and more specifically, to a wave motion machine that is mountable on a pier or large ocean vessel and continuously rotates a drive shaft to which a generator is attached.
Various devices have been disclosed for harnessing energy within ocean waves. Typically, a shaft is rotated when a float riding on a wave lifts a crankshaft, resting as the wave subsides until another wave again lifts the float. Thus, only half of the wave motion is captured. It is also typical that past wave motion machines require a limited range of wave amplitude to complete a rotation of a crankshaft, being nonfunctional with waves too small to complete a crankshaft rotation and perhaps disabling the machine when waves larger than anticipated overwhelm the machine.
The primary object of the invention is to continuously harness electrical energy from ocean wave motion using a machine operating from a stationary platform, such as a pier or a large sea-going vessel, under which ocean waves pass. It is also an object that the device operate on a large range of ocean wave amplitudes, adjusting to accommodate changes in wave amplitude. It is also an object that the machine extract wave energy both on the wave amplitude rise and on the wave amplitude fall. It is a further object that the device accumulate energy as necessary to enable energy to be continuously drawn from the device while a variable amount of energy is extracted from wave action.
These objects are achieved in a highly efficient wave machine that produces continuous power efficiently and economically. The machine easily operates from a pier or large ocean-going vessel with floats that ride on the surface of the water and drive a rotating shaft. The shaft then drives a generator to provide continuous electricity to an island cabin or well water pump, for example, or serve as an emergency back-up electricity supply. A plurality of gears is fixed to the shaft axially such that motion of the shaft causes the gears to rotate.
A plurality of floats intended to be positioned in a body of water are mechanically connected to a one-way clutch or ratchet on the shaft so that when the floats rise and fall as waves pass beneath them, the shaft rotates. (For descriptive purposes herein, we will use one-way clutch to represent all such one-directional drive means.) A pair of articulated connecting rods are connected to each float with one of the rods connected to a first shaft and the other connected to a second shaft, each connecting rod attached to a one-way clutch on the respectively shafts. When the float rises, the rod forearm member attached to the float on one end and pivotably to the rod upper arm member on its other end pushes the rod upper arm member up as its pivot connection elbows, rotating the rod upper arm member which is firmly connected to the one-way clutch. The rotating rod upper arm member thus causes the engaged clutch to rotate. The connecting rod pivot connection also unfolds to allow the float to rise above that connection to accommodate very large waves.
Thus, when a float rises the xe2x80x9cupxe2x80x9d connecting rod causes the xe2x80x9cupxe2x80x9d shaft to rotate as its clutch is engaged, however, when the float falls, that clutch disengages, allowing that shaft to freewheel. Likewise when the float falls the xe2x80x9cdownxe2x80x9d connecting rod causes the xe2x80x9cdownxe2x80x9d clutch to engage and the xe2x80x9cdownxe2x80x9d shaft to rotate, typically rotating opposite the rotation of the xe2x80x9cupxe2x80x9d shaft. When the float reverses and begins to rise again, the xe2x80x9cdownxe2x80x9d clutch disengages and the xe2x80x9cupxe2x80x9d clutch reengages. Thus, the wave does not need to lift the float a given height such as to cause a crank on the drive shaft to rotate around the shaft in order to impart energy to the shaft. Virtually any movement is captured by the one-way clutch and transfers that movement into rotational energy in the drive shaft. When the float falls before it reaches a machine shaft rotational apex, that clutch simply disengages and its complementary one-way clutch engages to capture the downward motion of the float, regardless of how high the float rose.
A connecting rod hand member may also be connected pivotably to the forearm at a wrist joint, and at that wrist joint the hand member, adjustable in length at the wrist joint to reach from the pier to an average water level, releases from the wrist joint if the float should rise to a level even above the unfolded arm length. Thus, if the wave were to be very large such that the float rises above the extent of the unfolded rod upper arm member, the float simply floats away from the machine on the pier. The float remains tethered to the arm to avoid loss of the floats. Energy is not captured in this unlikely event at this portion of the float movement, but the machine also is not damaged because the float is not constrained to ride on a given vertical path along the pier or within an artificial limitation of wave movement.
A plurality of floats with their attendant connecting rods and clutches typically are connected in series along the two shafts. In operation, as a wave passes under the series of floats, a first float will rise followed by a subsequent float so that the floats are out of phase. As each float is connected to the shafts, the shafts continue to rotate under the force of the rising and falling floats, each at a different phase. As one float is beginning to rise, another may be ending its rise and another may be midway down its fall, for example. Ideally, the number, size and spacing of the floats is such that a wave continues to exert force on at least one of the shafts at all times, therein providing continuous energy to the machine.
Typically, one or more drive gears mechanically link the two shafts with meshing gear teeth. An output shaft also mechanically links to the gears, commonly with an output gear with teeth meshing with one of the drive gears.
The output shaft is connected to a transmission to regulate and optimally drive a flywheel that is used to moderate and store extracted energy. An output one-way clutch is also connected between the transmission and the flywheel to disconnect the flywheel when the output shaft is not adding to rotation of the flywheel. A generator or other energy-consuming device is connected after the flywheel.